Accepted

Fibromyalgia is characterized by chronic widespread pain, mood and sleep disturbance. Pharmacological treatments have modest efficacy and are associated with negative side effects, and alternative approaches are needed. Morning bright light treatment may assist in the management of fibromyalgia as it can reduce depressive symptoms, improve sleep, and advance circadian timing.

In recent decades, studies have addressed the issue of how migraine and obesity are related and have suggested obesity as a risk factor for migraine headache. However, the exact direction of this relationship remains under debate. In this review, the authors summarize the evidence that have suggested migraine as a risk factor for obesity and overweightness.

The aversive aspect of pain constitutes a major burden faced by pain patients. This has been recognized by the pain research community, leading to the development of novel methods focusing on affective-motivational behaviour in pain model animals. The most common tests used to assess pain aversion in animals require cognitive processes, such as associative learning, complicating the interpretation of results. To overcome this issue, studies in recent years have utilized unconditioned escape as a measure of aversion. However, the vast majority of these studies quantify jumping – a common escape behaviour in mice, but not in adult rats, thus limiting its use. Here, we present the "Heat Escape Threshold" (HET) paradigm for assessing heat aversion in rats. We demonstrate that this method can robustly and reproducibly detect the localized effects of an inflammatory pain model (intraplantar carrageenan) in male and female Sprague-Dawley rats. In males, a temperature that evoked unconditioned escape following carrageenan treatment also induced real-time place avoidance (RTPA). Systemic morphine more potently alleviated carrageenan-induced heat aversion (as measured by the HET and RTPA methods), as compared to reflexive responses to heat (as measured by the Hargreaves test), supporting previous findings. Next, we examined how blocking of excitatory transmission to the lateral parabrachial nucleus (LPBN), a key node in the ascending pain system, affects pain behaviour. Using the HET and Hargreaves tests, we show that intra-LPBN application of glutamate antagonists reverses the effects of carrageenan on both affective and reflexive pain behaviour, respectively. Finally, we employed the HET paradigm in a generalized opioid-withdrawal pain model. Withdrawal from a brief systemic administration of remifentanil resulted in a long-lasting and robust increase in heat aversion, but no change in reflexive responses to heat. Taken together, these data demonstrate the utility of the HET paradigm as a novel tool in preclinical pain research.

In this study, Brillouin and Raman micro-Spectroscopy (BRamS) and Machine Learning were used to set-up a new diagnostic tool for Osteoarthritis (OA), potentially extendible to other musculoskeletal diseases. OA is a degenerative pathology, causing the onset of chronic pain due to cartilage disruption. Despite this, it is often diagnosed late and the radiological assessment during the routine examination may fail to recognize the threshold beyond which pharmacological treatment is no longer sufficient and prosthetic replacement is required. Here, femoral head resections of OA-affected patients were analyzed by BRamS, looking for distinctive mechanical and chemical markers of the progressive degeneration degree, and the result was compared to standard assignment via histological staining. The procedure was optimized for diagnostic prediction by using a machine learning algorithm and reducing the time required for measurements, paving the way for possible future in vivo characterization of the articular surface through endoscopic probes during arthroscopy.

Outcomes after spinal cord stimulator (SCS) placement are affected by psychologic comorbidities. It is part of routine practice to do psychologic assessments prior to SCS trials to assess for the presence of maladaptive behavioral patterns. However, few studies have sought to quantify the effect of psychiatric comorbidities on complications, reoperation, and readmission rates. The purpose of this study was to assess the association of psychiatric comorbidities with postprocedural outcomes after SCS implantation.

Headache, often migrainous, is common in patients with antiphospholipid antibodies, whether or not they meet Sydney criteria for a definite diagnosis of Hughes syndrome. Migraine may be a harbinger of stroke in this patient population and even refractory migraine may be highly responsive to antithrombotic therapy in this clinical context.

This study aimed to investigate changes in dynamic functional network connectivity (FNC) in patients with vestibular migraine (VM) and explore their relationship with clinical manifestations.

Repetitive movements (RM) are a main risk factor for musculoskeletal pain, which is partly explained by the overloading of musculoskeletal structures. However, RM may also drive brain plasticity, leading to maladaptive changes in sensorimotor areas and altered pain processing. This study aimed to understand whether individuals performing extensive RM (musicians) exhibit altered brain processing to prolonged experimental muscle pain. Nineteen healthy musicians and 20 healthy non-trained controls attended three sessions (Day1-Day3-Day8). In each session, event-related potentials (ERPs) to non-nociceptive superficial and nociceptive intra-epidermal electrical stimulation, reaction times (RTs), electrical detection thresholds (EDTs), and pressure pain thresholds (PPTs) were recorded. In all participants, prolonged muscle pain was induced by intramuscular injection of nerve growth factor (NGF) into the right first dorsal interosseous muscle at the end of Day1. Pain intensity was assessed on a numerical rating scale (NRS) and was lower in musicians compared to non-musicians (p<0.007). Compared with Day1, NGF reduced PPTs on Day3-Day8 (p<0.001) and non-nociceptive P200 and P300 ERP amplitudes on Day8 (p<0.044) in both groups. Musicians compared to controls showed secondary hyperalgesia to electrical stimulation on Day3-Day8 (p<0.004) and reduced nociceptive P200 ERP amplitudes on Day8 (p<0.005). Across participants, ERP components correlated with pain detection (RTs), sensitivity (PPTs and EDTs), and severity (NRS), (all p<0.043). In musicians, the amount of weekly training was associated with higher NGF-induced NRS pain scores on Day3-Day8 (p<0.037). These results show that repetitive sensorimotor training leads to brain changes in the processing of prolonged pain, biasing the cortical response to nociceptive inputs.

Chronic pain remains a significant burden worldwide while treatments are often limited by safety or efficacy. The decarboxylated form of L-arginine, agmatine, antagonizes N-methyl-D-aspartate receptors, inhibits nitric oxide synthase, and reverses behavioral neuroplasticity. We hypothesized that expressing the proposed synthetic enzyme for agmatine in the sensory pathway could reduce chronic pain without motor deficits. Intrathecal delivery of an adeno-associated viral vector carrying the gene for arginine decarboxylase prevented the development of chronic neuropathic pain as induced by spared nerve injury in mice and rats and persistently reversed established hypersensitivity 266 days post-injury. Spinal long-term potentiation was inhibited by both exogenous agmatine and AAV-hADC vector pre-treatment but was enhanced in rats treated with anti-agmatine immunoneutralizing antibodies. These data suggest that endogenous agmatine modulates the neuroplasticity associated with chronic pain. Development of approaches to access this inhibitory control of neuroplasticity associated with chronic pain may yield important non-opioid pain-relieving options.

Seriously ill patients often experience persistent pain. As a part of a comprehensive repertoire of pain interventions, palliative care clinicians can help by using behavioral pain management. Behavioral pain management refers to evidence-based psychosocial interventions to reduce pain intensity and enhance functional outcomes and quality of life. Conceptualized using the biopsychosocial model, techniques involve promoting helpful behaviors (e.g., activity pacing, stretching, and relaxation exercises) and modifying underlying patterns of thinking, feeling, and communicating that can exacerbate pain. The authors have expertise in pain management, clinical health psychology, geropsychology, behavioral science, and palliative medicine. The article reviews the current evidence for behavioral interventions for persistent pain and provides 10 recommendations for behavioral pain management.